Field of the Invention
The present inventions relate to at least one zoom lens and at least one imaging apparatus including the at least one zoom lens. The at least one zoom lens is suitable for an imaging apparatus in which an image sensor is used, such as, but not limited to, a digital still camera, a video camera, a monitoring camera, and a broadcasting camera. The at least one zoom lens is also suitable for an imaging apparatus such as a camera using silver-halide photographic film.
Description of the Related Art
Recently, an imaging apparatus employing a solid-state image sensor, such as a digital still camera and a video camera, has been high-functionalized, and the entire size thereof has been reduced. A zoom lens used in such an imaging apparatus is required to be short in total lens length and high in resolution.
In a zoom lens discussed in Japanese Patent Application Laid-Open No. 2012-47814, a plurality of lens groups located on an image side relative to an aperture diaphragm moves during focusing. In the zoom lens, by using a plurality of lens groups for focusing, a refractive power of each focus lens group is relatively weakened.
Generally, to obtain an imaging optical system having a high resolution, it is important to determine an appropriate configuration in a focus lens group in the imaging optical system.
If a focus lens group is not properly configured, it is difficult to satisfactorily prevent the occurrence of an aberration variation caused by focusing.